Romney promotes himself as a "son of Detroit," who left to conquer the business world. His carefully scripted rallies feature not only reminiscences of the old Detroit area neighborhood but reminders of his history as a successful corporate turnaround artist.

Santorum, a former U.S. senator from Pennsylvania, offers a different story. He roared into Michigan with strong momentum, having won three contests earlier this month. His freewheeling stump speeches usually are laced with heartfelt reminders of his devotion to God and family.

Polls have shown him in a virtual tie with Romney, the former Massachusetts governor. A Romney loss in a state where, on paper, everything should go his way would be viewed as a serious blow. A Santorum defeat would raise fresh questions about his appeal beyond diehard conservatives.

A victory by either man would demonstrate appeal in a blue-collar industrial state and give him an important boost in next week's primary in neighboring Ohio.

Michigan Republicans are torn. Do the residents of this economically ailing state put aside their skepticism about the depth of Romney's conservatism and choose the businessman who seems best positioned to win in November? Or do they follow their heart and pick Santorum? And where does Texas Rep. Ron Paul, who is waging a vigorous campaign this weekend, fit?

Ground Zero may as well be Shelby Township, a Detroit suburb visited by both Santorum and Romney in recent weeks. It's part of an area well known in political circles as the suburbs that made famous "Reagan Democrats," rank-and-file workers who felt Democrats let them down economically and culturally and began voting Republican in the 1980s.

"The jury's out on who people like most," says franchise owner David Danyko.

Customers Stan Grot, Bo Chapman and Mike Torres have similar views — solidly conservative, eager for lower taxes and less regulation, wary of President Barack Obama.

Grot's for Romney. Chapman prefers Santorum. Torres likes Newt Gingrich, the former House of Representatives speaker who's making virtually no effort here.

Grot, the township clerk, worked in manufacturing engineering at General Motors. He lost his job in 1980, spent a year on unemployment and left the Democratic Party.

"I listened to Ronald Reagan's message," he recalls. "Ronald Reagan spoke to opportunity and personal responsibility. He created an environment so businesses could thrive."

Grot liked how the 1981 tax cuts put more money in consumers' pockets, and he opened a restaurant in Hamtramck. He ran it for eight years before selling the place; it's still thriving today.

Grot is solidly for Romney. "He comes as close to the Ronald Reagan message as I can think of," he says.

Chapman, director of student ministries at St. Peter Lutheran Church in Macomb, thinks Romney's a fine man. But he likes how Santorum is reaching higher, promoting strong families and more personal responsibility.

"He can impact the lives of people in a powerful way," Chapman explains. "I love it when he talks about family. That's so important to address before you get too far off on economic issues."

Grot counters that "there's no consistency with Santorum." He cites Senate votes to raise the debt ceiling and to approve a budget that included funds for Planned Parenthood. He suggests Santorum is too extreme; Chapman disagrees.

At a nearby table, Torres says Romney is "too nice of a guy." He likes Santorum, but "he follows the Bible as a politician, and he's going to get beaten."

A Macomb builder/developer who has seen his business go up and down recently, Torres likes Gingrich's brash style.

Attitudes like those at Baggby echo throughout the state. People are warming to Santorum, and they like his social conservative message, but they worry he's not electable.

They respect Romney but want to see more passion and more genuine concern for blue-collar workers. They fret over his criticism of the auto industry bailouts, support of near-universal health care in Massachusetts, and his ties to Wall Street.

Romney was asked about his corporate ties at a tea party rally in Milford. "I don't apologize for success," he said.

He got warm applause from the crowd, telling stories about his "many years in this great state." He described his economic plan, including a 20 percent across-the-board cut in income tax rates, and he bashed Obama as unqualified to be president.

His strategists insist a Michigan loss will not be a huge psychological blow. Romney also claims New Hampshire and Massachusetts as home states, said senior adviser Ron Kaufman, "so we'll probably win two out of three." Romney won New Hampshire last month, and Massachusetts holds its primary March 6.

Santorum tries hard to stay on the subject of economics but invariably winds up describing his background as the son and grandson of immigrants and his long devotion to social conservative issues.

"I worked my way to the success that I have and I'm proud of it," he told a crowd of conservatives Saturday in Troy, a Detroit suburb. "I wasn't for Obamacare, Romneycare or any other care except your care. I wasn't for bailouts."

Conservatives love it.

"I like his stand on abortion and same-sex marriage. I'm a good Catholic, and he's a good Catholic," said David Hollobaugh, an Allen Park retiree. "He reminds me of my son, clean cut and moral," said Barbara Thomas, a Taylor retiree.

But can social issues provide enough momentum to topple Romney? Can Romney's economic message trump conservatives' appreciation of Santorum's views?

The jury remains out.

Barbara Ziemba, a Livonia administrative assistant, heard Romney recently in Milford. "I like what he said," she said. "But I just haven't made up my mind."

Many echoed the view of Dee Kubic, a Farmington Hills housewife at the same rally. When she goes to the polls, she said, her choice is "going to be a gut feeling."